1. Field of the Invention
The invention relates to a stack of interfolded absorbent sheet products, and preferably, but not necessarily, to a stack of interfolded paper napkins bearing a predetermined pattern imparted by embossing or by formation by Through-Air Drying (“TAD”) or by a structured tissue technique.
2. Description of Related Art
In commercial food service establishments and public restrooms, folded paper products such as paper napkins are typically provided in dispensers from which the products may be withdrawn by the patrons of those establishments. Whereas the highest quality paper napkins are invariably “server-controlled,” i.e., delivered individually by a waiter or waitress, it is nevertheless desired to provide paper products in the user-dispensed application that are perceived as being of relatively higher quality.
Interfolded paper products, and especially interfolded paper napkins, have the advantage that they can be loaded into a dispenser whose faceplate cooperates with the stack of napkins to encourage users to remove napkins one at a time. This results in users taking fewer napkins than if it were possible or encouraged to remove a group of napkins simultaneously, although the paper product stack according to the invention may be used in dispensers that promote either one at a time or group dispensing.
Interfolded paper napkins applied to a user-dispensed environment include those that are single folded only. Patent literature describes a variety of arrangements of interfolded paper napkins having plural parallel folds, for example, in U.S. Pat. Nos. 5,118,554, 6,090,467 and 6,213,346.
Paper napkins that are single folded only (sometimes also called “half-folded” when the fold bisects the napkin, or “off-folded” when it does not) have the disadvantage that, in order to achieve a given total absorbency, the basis weight of the unfolded napkin sheet must be relatively high. This in turn causes the napkin to have relatively low softness and drape properties, both of which properties are important to the user's perception of the total quality of the napkin. The provision of plural parallel folds in a napkin has the obvious limitation that the napkin will have a relatively elongated shape in the direction parallel to the folds, unless the starting blank is cut to a relatively more elongated shape in the direction perpendicular to the folds.
Such interfolded paper napkins also include those that are folded at least twice about axes that are perpendicular to one another, as described in commonly-owned U.S. Pat. No. 7,611,765, the entirety of which patent is hereby expressly incorporated by reference. In embodiments of that patent wherein two folds each bisect the base napkin sheet, the area of the unfolded sheet will be approximately four times that of the folded napkin.
U.S. Published Patent Application No. 2010/0055391 describes an array of folded sheet materials in which each sheet is first folded along a “medial” fold and then folded in a perpendicular direction in an “off-fold” location. However, an interfolded stack of such materials is subject to certain limitations as regards its appearance and dispensing, as discussed herein.